Compressed gas operated harpoon gun



May 23, 1967 .1. G. HOUGHTON 3,320,941

COMPRESSED GAS OPERATED HARPOON GUN Filed sept. 27, 1965 4 sheets-sheet1 m, 5. um. E oz.

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COMPRESSE!) GAS OPERATED HARPOON GUN Filed sept. 2v, 1965 4 sheets-sheet2 No. t/ fm1/i5@ oN/ J \T Il A i .M

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nm@ eww du@ www mmm ` .NSM Si @TQQ mmv nmmd May 23, 1967 J. G. HOUGHTONCOMPRESSED GAS- OPERATED HARPOON GUN 4 Sheets-Sheet 4 Filed Sept. 27,1965 .0. E mL MW United States Patent O 3,320,941 COMPRESSED GASOPERATED HARPOUN GUN John George Houghton, 245 Camden Road', Parsippany,NJ. 07054 Filed sept. 27, 1965, ser. No. 495,020 17 Claims.. (Cl.124-15) This specification is a continuation-in-part of my applicationSer. No. 287,340 tiled June 12, 1963, and now abandoned.

This invention relates to spear guns and more particularly to manuallyoperable guns such as are used for underwater spear shing,

Even more particularly this invention relates to spear guns of thepneumatic and hydro-pneumatic type and in particular to a spear gunwhich is convertible from pneumatic to hydro-pneumatic operation andback again as is shown in one embodiment of my invention in which Iprovide a gun whose chamber is adapted to be hydraulically charged `or`be operable solely as a compressed air propulsive gun.

Manually operated spear guns heretofore used for underwater speariishing have generally used bands, spring mechanisms, pneumatic orhydro-pneumatic as the propelling means for the spear. In each case thetiring force is generally obtained by manually inserting the spears inthe guns to stress the elastic bands or springs or to compress the air.The characteristics iand limitations of the spring and rubber typesbeing generally known, only the hydro-pneumatic and pneumatic types willherein be discussed.

The pneumatic spear gun which utilizes a piston as the propelling meansfor the spear presents several unique` problems, the piston, uponrelease from the triggering means, travels forward with high velocity inorder to drive the spear or harpoon out of the barrel. The effectiveperformance of this function requires that the piston must do thefollowing: it must be capable of restraining the spear from falling outof the barrel due to gravity; it must have efcient means fordeceleration or shock absorption at the termination of its travel, andit must be capable of sealing compressed air up to 600 p.s.i. The impactof the piston, upon reaching the stop means at the muzzle, lcreates asharp sound which is clearly audible for some distance under water. Ithas been observed that in certain underwater areas, particularly wherespearshing activity has been extensive, this sound may tend:

to make the tish rather wary and difficult to approach. Although theselimitations can be overcome to a great degree, as will be shown in thepresent invention, a single purpose spear gun of this type may be ahandicap to the user.

On the other hand, the hydro-pneumatic spear gun is relatively silent inoperation, even when the gas filled accumulator is of the piston-type.The reason for this is that the piston need only travel a short distanceand at a relatively low rate of speed in order to purge the column ofwater which is used to drive the spear from the barrel. Further, theWater in the system, serves to cushion the piston, at its termination oftravel. Another advantage in the hydro-pneumatic type gun is that thereis no need to retain the spear in a piston, as the rear end of the spearcan be mechanically detented by the triggering device. For this reasonit is to be noted that many skin diving clubs and organizations arestrongly opposed to loading or carrying loaded spear guns on or nearpublic beaches. With the hydro-pneumatic gun, this possibility isminimized due to the necessity of iilling the barrel with water in orderto facilitate loading. The main disadvantage to the hydro-pneumatic gunis that for a given average ring force, the nal loading force must behigher than that of a pneumatic spear gun. This is main- ICC ly due toloss of power caused by friction of water iiowing through the system.Therefore, when maximum power, with minimum loading effort, is desired,the pneumatic spear gun has decided advantage. In View of the foregoing,it is evident that a spear gun with combined facility for utilizingeither the pneumatic or the hydropneumatic principle of operation andwhich can be adapted to either principle, by the user, is highlydesirable.

It is an object of this invention to provide an underwater spear gunwhich is compatible to both pneumatic and hydro-pneumatic principles ofoperation. It is a lfurther object of this invention to provide a speargun which may be used with a minimum of .adjustment in either the purelypneumatic or in a hydro-pneumatic form of operation.

Another object of the invention resides in the provision of an improvedspear gun utilizing a sealed compressed air supply with provisions forexternal pumping means.

Still another object of the invention resides in the provision for anair operated improved trigger safety device.

A still further object of the invention resides in the provision for aone-piece, opposing pressures operated, trigger coupled, spear andpiston latching device.

A still further object of the invention resides in the provision for animproved air propelled dual piston with air operated deceleration means.

A still further object of the invention resides in the provision of animproved spear gun utilizing a muzzle assembly with air-operated shockabsorbing means.

A still further object of the invention resides in the provision of animproved spear and spear retrieving collar.

It is a still further object of this invention to provide an underwaterspear gun of moderate cost,l easy to use, light in weight, reliable,extremely powerful, accurate and well balanced. The gun of thisinvention is intended to be readily adjustable so that loading forcescan be` va-ried as desired by the user.

In the attainment of these and other objects 'as found in the presentinvention, in one embodiment I provide a gun of hydro-pneumaticoperation and having a firing tube carried by `a handgrip. This tube isadapted to receive the shank end of a spear having a. shaped end adaptedto act as a piston-this end `also having a detent means adapted to beengaged and released by a trigger mechanism carried by the handgrip.Said trigger mechanism having a safety device for preventing theunintentional release of an armed gun. In yet another embodiment Iprovide ya gun adapted for pneumatic operation and similar in mostrespects to the gun of hydro-pneumatic operation except that the tiringtube has a nosepiece or check member to retain a movable piston slidablein the bore of the firing tube.

In still another embodiment of my invention I provide a gun readilyconvertible from pneumatic `to hydropneumatic operation and back again.This convertible gun is similar in most respects to the guns above,howver, there is provided a novel valve for permitting the lrear orinternal portion of the tiring tube to be opened to a pneumatic springassisted chamber. A novel pneumatic cushion is also shown in conjunctionwith this embodiment.

In the accompanying drawings is shown the spear gun in the variousembodiments as outlined above. In one embodiment the gun is arranged to-be used in a lhydro-pneumatic manner while in another embodiment thegun is arranged to be used in a pneumatic manner. In yet anotherembodiment is shown the spear `gun arranged -to be used `as a pneumaticgun and with the same components to be readily convertible byrearrangement Patented May 23, 1967 of certain members into ahydro-pneumatic gun and readily reconvertible into a pneumatic gun.

It is Iunderstood that the drawings are illustrative of the inventionrather than limiting the invention.

`In the drawings:

FIGURE 1 represents a side view showing the general arrangement of thegun and spear and particularly when arranged for hydro-pneumatic use;

FIG. 2 represents a longitudinal View, mainly in secon and in enlargedscale, Iof the spear land gun of FIG. 1;

FIG. 3 represents a sectional view taken on the line 3 3 of FIG. 2 andshowing the trigger mechanism for holding the spear in armed position;

FIG. 4 represents a side view of a spear gun similar to the gun of FIG.l but with a gun arranged for pneumatic use;

FIG. 5 represents a longitudinal view, mainly in section and in enlargedscale, of the spear and gun of FIG. 4;

FIG. 6 represents a sectional view taken `on the line 6 6 of FIG. 5 andshowing the trigger mechanism with the safety mechanism in a differentposition than in the View of FIG. 3 and with the spear in armedposition;

FIG. 7 represents a sectional view of a handle portion taken on the line7 7 of FIG. 5;

FIG. 8 represents a sectional view of a handle portion taken on the line8 8 of FIG. 2;

FIG. 9 represents a sectional view taken on the line 9 9 of FIIG. 14;

FIG. 10 represents a cross sectional view of a muzzle portion of anotherembodiment of a gun in pneumatic arrangement and showing the piston andfiring tube and with the spear and retrieving ring at the moment thepiston arrives at the end of its travel;

FIG. 11 represents a sectional view similar to FIG. 10 but showing thepiston just prior to its reaching the end of its travel;

FIG. 12 represents a sectional view of a muzzle portion of yet anotherembodiment of a gun of hydropneumatic form and showing the spear andretrieving ring of FIG. 10 as adapted to this embodiment;

FIG. 13 represents a cross sectional View of the retrieving slide ofFIG. 9 and showing the slide members prior to the assembly thereof;

FIG. 14 represents a modication `of the gun of FIG. 5 in which the spearand retrieving ring of FIG. 10 and a valve check is added to Ithe muzzle`of the gun of FIG. 5;

FIG. 15 represents a sectional view similar to FIGS. 2 and 5 and showinganother embodiment of a gun adapted to be used in either a pneumatic orhydropneumatic manner and with the muzzle adapted for hydro-pneumaticuse;

FIG. 16 represents a sectional view of the muzzle of the gun of FIG. 15with the gun conver-ted for pneumatic use; and

FIG. 17 represents a sectional view 4of yet another embodiment of amuzzle adapted for use as a pneumatic gun.

Referring now more particularly to the drawings in which like numbersrefer to like members, the hydropneumatic gun and spear exemplied byFIGS. 1 through 3 include a handgrip 1 which is preferably made of ahigh impact plastic, and which is so formed as to provide `a triggerhousing. A tiring tube 2 is carried by the handgrip 1, said tube beingthreaded at the handgrip end and screwed into a threaded opening 2aprovided in the handgrip and sealed therein by means `of an O-ring 3.The ring tube 2 is a long, smooth bored tube of generally the samediameter and having the muzzle end formed with a reduced external outerportion of relatively short length and then an external threaded portion2b adapted to receive the internally threaded portion of a anged adapter4. This adapter 4 is additionally provided with a larger threaded boreportion 4a into which is screwed the externally threaded portion of anose section S. Nose sec-tion 5 is further formed with a concentricallytapered bore 5a. A spear retrieving slide 6 has a portion thereof formedinto a concentric conical rear section `6a which mates with and isseated in bore 5a. In addition to providing a connection to the spear,retrieving slide 6 has a bore therein adapted to center the spear 21 inthe firing tube in order to provide maximum accuracy of the spear duringits flight after being released from the gun. A description of theoperation of the slide in the retrieving of the spear will appear belowin connection with the description of the loperation of the gun. As seenin FIG. 2, the rear end of handgrip 1 is formed with an external thread1a with which to receive an internally threaded end of a tube 7 whichforms the outer wall of a compression chamber. An O-ring 8 is tted intoa recess adjacent thread 1a and provides a seal of the threaded joint oftube 7 and handgrip 1. A tapered passageway -9 extends from the interiorend of ring tube 2 through the handgrip and to its end this openingjoining the interior chamber of tube 7. The interior of tube 7 forms anair accumulation chamber 7a which carries a slidable piston 10 which hasan O-ring 11 acting as a piston ring. Shoulder 1b formed of the end wallof handgrip 1 provides a stop means for the forward motion of piston 10.The piston 10 has a relief 10a formed therein in order to reduce itsmass or weight. Tube 7 has its unattac'hed end internally threaded at 7bwhich thread receives and retains a check valve retainer 12. An O-ring13 carried in a groove adjacent the external threaded portion ofretainer 12 provides a sealing means between tube 7 and retainer 12. Acheck valve 14 as conventionally used in tire stems or tire tubes isthreadedly carried by an internal threaded recess 14a in valve retainer12. An O-ring 15 may be used to seal the check valve 14 in recess 14a. Athreaded plug 16 is mounted in an enlarged internal threaded recess 16aat the rear end of retainer 12 and is sealed therein by means of anO-ring 17. A formed wire loop or catch 18 is pivotally mounted inopposed blind holes in plug 16 and is conventionally used to facilitatethe attachment of a securing line from the gun to a -towable oat. Theloop also serves as a tool with which to turn plug 16 so as to removethe plug from the retainer 12 so -that lan air pump (not shown) of theconventional hand operated tire pump type may be employed to chargecompressed air linto chamber 7a, the check valve 14 acting in aconventional manner to retain the air forced into the chamber 7a. Acombination balance `and inertia damping weight 19, preferably made oflead, is disposed at the rear of and within tube 7. An air passage 19ain weigh-t 19 provides a passageway for air to be admitted into the airchamber through check valve 14. A screw 20 carried by Weight 19 entersretainer 12 and secures weight 19 to retainer 12. Of note is weight 19which provides a balance for the mass of the spear 21 when it is mountedin the barrel of the gun. This providing of a balance permits the gun tobe used with one hand, leaving the other hand free for swimming or otherpurposes. The balance weight also aids in absorbing Athe reactionaryforces imposed when tiring the gun and thus improves the accuracy of thespear as it is fired from the barrel of the gun.

A spear 21 as seen in FIGS. 1 and 2 is disposed in the gun in an armedposition in tube 2. In this position the retrieving slide 6 is disposedjust to the rear of a spear point 22 which may be attached to spear 21by means of a threaded portion of the spear point which is screwed intoa threaded recess 21a of the spear, A fuller description of slide 6 andalternate embodiments appear later in the description. A conical section6a of retrieving ring 6 is `adapted to seat and be tightly held by atapered bore 5a formed in the nosepiece 5.

A retrieving cord 23 extends from a yieldable hooklike member 24 whichis mounted upon or is positioned around the rear portion of tube 7. Thishook is conventionally made of rubber or of a flexible plastic. Thishook member 24 engages the cord at about its middle and one portion 23aof the cord extends forward and is threaded through a hole 25 in theil-ange of adapter 4 and is secured thereto. The other end 23b of thecord is brought forward from hook 24 and secured to a shorter cord 26which is threaded at both ends through a pair of holes 27 in the ears ofretrieving slide 6r. The rubber hook 24 provides a sufcient bias tomaintain the retrieving cord 23 in a taut condition.

The spear 21 conventionally has a long cylindrical shank portion whichis slidable in the bore of slide 6 with the point and the threadedlyengaged portion 21a extending beyond the slide 6. The rear end of thespear 21 has formed therein a threaded recess 2lb which receives andretains a short, cylindrical, spear adapter 28 having a diameterslidable in the bore of tube 2. In this diameter is provided an annulargroove for O- ring 29 which acts as `a piston ring for adapted 23 andwhich acts as a gas or fluid seal in the bore 2c of ring tube 2. Anannular ange 28a is formed at the rear of the adapter 28.

The trigger mechanism is retained in handgrip 1 and as seen in FIGS. 2and 3 is illustrated in the armed position. A cylindrical latch 3&1 isslidably carried in a vertical diametral recess 1c and reduced diametralrecess 1d of handgrip 1. This latch lies between passage 9 and the end2a of tube 2 and is provided with a transverse bore 30a which connectsthese two passages. This bore 30a is tapered at the forward end and isidentiiied 30h while the rear of the bore is recessed as 30e and forms alatching shoulder for engagement with annular flange 28a of the adapter28. An O-ring seal 31 is carried in an annular groove in the largerdiameter portion of latch 30 while an O-ring seal 32 is also carried inan annular groove in the smaller diameter portion of latch 30. S-eals 31and 32 prevent flow to and from the outside of the ygun to thepassageway extending from 9 to tube 2 and also impose an urging force inthe upward or latching direction on latch member 30'. This force itsprovided by the internal water pressure reacting on the greater annulararea of seal 31 as opposed to the lesser annular area of seal 32 whenthe gun is in the -armed condition. Unlike conventional guns thisprinciple foregoes the necessity of a mechanical spring to return thelatch to the latching position. The lower end of the latch 30 is areduced portion and has a slot 33 transversely formed to the -axis ofthe latch. A pin 34 is slidable in this slot and engages a triggermember 35 in a slot 35a. The member 35 is pivotally retained by a pin 36which -is rotatable in the hole formed in the member 35. The pin isnon-rotatably secured in a transversely disposed hole in reduced por--tion 41 of handgrip 1.

The safety mechanism associated with the trigger mechanism describedabove is illustrated in FIGS. 2, 3, 5, 6 and 7, and includes a piston 37having a spherically formed left or forward end and having an annulargroove at Ithe opposite end .adapted to seat therein an O- r-ing 38. Asafety member 39 is slidably and pivotally retained in recess 40 formedin the handle portion of handgrip 1. A blind hole 39a in member 39provides a bore for the insertion and movement of piston 37 which as itis inserted Iin-to the hole 39a forms a miniature pressure chamber asthe atmospheric air trapped therein is compressed by the inward movementof the piston 37. This reactionary force on piston 37 urges it forwardlyagainst the rear of trigger member 35 which engages pin 34 to urge latch30 upwardly into latching position. This contained pressure urgingpiston 37 for* wardly causes member 39 to be preloaded toward the olfposition as best seen in FIGS. 5 and 7. Trigger member 35 is locked inthe safety condition by manipulation of lug 39h which is urged to theleft or forward with the thumb of t-he hand holding the gun (projectinglug `39b of safety member 39 may be arranged to accommodate either leftor right hand operation) until the rear of the projection 39b isdisplaced from slot 42 formed in the handgrip 1. The projection is thenrotated to a downward position as illustrated in FIGS. 2, 3 and 8. Thislug 39b now becomes a rigid member disposed between the rear of trigger35 and surface 43 of handgrip surface 43 acting as a shoulder `stop 1thereby preventing an accidental actuation of trigger 35. The volume ofair in pressure chamber 39a is thus further reduced by the forwardmovement of member 39 causing a greater pressure in this chamber,furthe-r urging trigger 35 forward. lt is to be noted that plunger 37could be urged forwardly by means of a compression spring rather than apressure chamber. Such a spring (not shown) would preferably be made ofa metal that would resist rust and corrosion likely to develop becauseof exposure to salt and/or fresh water. To deactivate the safety device,the lug 39b is rotated upwardly to engage slot 42 whereupon thecompressed air in chamber 39a urges the lug rearwardly into the slot. Ableed passage 40a is provided from the rear of "bore dt) to the exteriorof handgrip 1 so that any trapped water or air behind the moving member39 will not be trapped in the bore 40 but will be purged therefrom.

Operation of gun in hydro-pneumatic form To operate the gun of FIGS. 1through 3 the following procedure is preferably followed: the :air inchamber 7a is brought to the desired pressure by the admitting ofcompressed air through the check valve 14 while plug 16 is removed fromthe handgrip. Plug 16 is then reinserted into the retainer 12. The gunis then submerged to allow the barrel to be filled with water whichcompletely lls bore 2c, transverse bore 30a and hollow passage 9.Adapter 28 is inserted into the nose section 5. Slide 6 is mounted inthe tapered portion 5a and then the gun is 4armed by manually forcingthe spear through the barrel toward the rear of the gun. A loadingdevice of conventional construction (not shown) is usually used toassist in inserting the spear. O-ring 29 acts as -a seal to prevent thewater in the barrel from leaking past the spear with the rearwardlyurged water forcing the piston 10 rearwardly to compress the air inchamber 7a. rllhe spear is pushed into the gun until the annular flange28a of the adapter 23 passes through bore 36a of latch 30 and the flangeis engaged by the shoulder of the latch 30 and takes the armed positionas shown in FIG. 2. Safety 39 is manipulated so that lug 39h is in thedownward position as described above and with the safety activated thecord 23 is stretched over yieldable hook member 24 and held thereon. Tore the gun, the safety device 39 is first released by turning lug 39bupwardly, usually with the thumb of the hand holding the gun, thencesqueezing or pulling the trigger 35 with the forenger of the graspinghand.. The trigger, when pulled, causes pin 34 to be moved downwardlysimultaneously moving member 30 downwardly so as to cause the shoulderof -member 3@ to disengage from flange 28a. The spear assembly nowreleased is free to move through the barrel whereupon the compressed airin chamber 7a moves the piston lll toward the spear 21 forcing thetrapped water between the end of the adapter 23 and the piston 10 tomove forwardly to eject the spear from the barrel. Prior to leaving thebarrel, the rear adapter 28 of the spear 21 engages retrieving slide 6and urges the slide from its seat in nose piece 5. The slide 6 attachedto cord 26 thence to cord 23, is carried by the movement of the spear tocause the cord 23 to tighten forcing yit to pull away from yieldablehook 24. The spear, now completely free of the gun, travels until ithits its mark or until the cord 23 is pulled to its limit. The spear isretrieved by pulling the cord 23 toward the gun. As

Pneumatic gun The -guns of FIGS. l-3 adapted to be changed from ahydro-pneumatic gun to a pneumatic gun with an interchange of relativelyfew parts. Those parts that are like parts carry like numbers andfunction in like manner and in FIGS. 4 through 6 illustrate anembodiment that is arranged to operate as a pneumatic spear gun. In FIG.5 it is noted that piston lll is not present in the chamber '7a and maybe removed by unscrewing retainer 12 from tube 7 and pushing piston l0from the chamber. The retainer 12 is then reassembled forming a 4largerchamber 7a and providing a free passage of lair from chamber '7a throughpassage 9 thence through bore 30a and finally through the bore 2c of thetube 2. Slidably disposed within and completely closing the bore 2c ofthe tiring tube 2 is a piston 44 which is similar in shape to theadapter 28 discussed above. This piston 44 is provided with an annulargroove which retains an O-ring 45 which acts as .a piston sealing ringfor piston 44 and tube 2. The rear end of this piston is formed with anannular flange 44a which forms a latching shoulder similar to shoulder28a. This ange 44a is retained and engages latch 30 as described above.In the recess 2lb of spear 2l is a tailpiece 46 which is threadedlymounted therein. A shouldered portion 46a, which when mounted liesadjacent the end of spear 2l, is of a slightly larged diameter than theshank of the spear. The rear portion of tailpiece 46 is formed with aconical portion 46b which is adapted to be held in a cone seat 44hformed in the forward portion of piston 44. The conical portion and seatis similar to the conventional taper lock as used on machine tools, andproviding sufficient restraint when assembled to prevent the spear fromfalling out of the piston from a force such -as gravity, but lightenough to allow ready separation upon the tiring of the gun. The forwardor muzzle end of the tube Z is provided with a nosepiece 47 which isexternally threaded so as to be mounted in thread 4a in adapter 4 afternose 5 is removed therefrom. This nosepiece is formed at its forward endwith a concentrically bored hole 47a and a concentric counterbore 47h inits rear portion. An annular internal recess is provided Within bore 47afor the mounting and retaining of an O-ring 48. A piston member 49 isslidable within nosepiece 47. The O-ring 48 provides a slidable sealbetween nosepiece 47 `and a similar external diameter 4% of piston 49. Alarger diameter 4% is formed at the rearward end of the piston and agroove is provided therein for the 4retention of an O-ring 5! which actsas a seal between surfaces 47b 4and 491:. Piston member 49 is `alsoformed with a concentric bore 49C adapted to slide freely on the shankof the spear 21 and with a concentric taper 49d at the forward end whichtaper is adapted to receive the conical section 6a of -retrieving slide6. INosepiece 47 and piston 49 combine with the seals as outlined `aboveto provide a shock absorbing muzzle assembly.

The assembly and operation of this shock absorbing muzzle unit is asfollows: piston 49 with an O-ring Sil mounted thereon is 4inserted intonosepiece 47 having an O-ring 48 mounted therein. With small diameter49a inserted in bore 47a the nosepiece 47 is threaded into recess 4auntil seated -as in FIG. 5. As thus assembled an annular recess 51 isformed with seals 48 and 5@ acting to retain the air that is trappedtherein during assembly. Recess 51 thus becomes a small compressed airchamber. When desired, a small check valve 52 of the conventional tiretube type and mounted as illustrated in FIG. 14 may be used to provide apassageway through which may be added compressed air. The concentricbore 49C of piston 49 is of a diameter to permit the free passage of theshank of the spear but is smaller than the bore 2c of the firing tube sothat the piston 44 as it moves forwardly in the barrel engages and isstopped by the inward shoulder of the piston 49.

Operation of gun in pneumatic form The pneumatic form of the gun as inFIGS. 4-7 provides that the air chamber 7a as Well as the barrel portionbehind barrel piston 44 be charged with compressed air through the checkvalve 14 and in the manner described for the hydro-pneumatic gun. rlhespear 21 with retrieving ring 6 thereon is inserted into the open end ofthe muzzle With the tapered portion 6a seated in the concentric taper49d of piston 49. Tailpiece 46 is now inserted through the open end ofthe muzzle piston 49 and is seated into cone seat 4419 of barrel piston44. The gun is armed or cocked by manually forcing the spear through thebarrel toward the rear of the gun and usually there is utilized aloading device of the conventional type as is used to load conventionalspring guns. The piston seal provided by O-ring 4S prevents thecompressed air in the barrel from leaking past the piston 44 thus theair in the gun is further compressed as the spear is forced through thebarrel. As the piston is pushed down the barrel the rear annual flange44a of the piston passes through bore 30a of latching device Si) andengages the latching shoulder as described above. The safety device ismanipulated as described in the hydro-pneumatic gun and is red in thesame manner. The cord 23 is stretched as described above and When thegun is tired the latching member 30 disengages from flange 44a andpiston 44 is released to rush forwardly as urged by the compressed airin chamber 7a. The movement of the piston pushes the spear forward athigh velocity. The piston is decelerated by means of the shock absorbingmuzzle unit in which piston 44- as it reaches the muzzle engages thepiston 49 and forces this piston forward. As this piston 49 movesforward it compresses the air in chamber 51 until suflicient pressure isbuilt up to stop the forward motion vof the barrel piston 44. The ratherabrupt stop of the piston 44 causes spear tailpiece 46 to disengage fromthe tapered bore 44h and to pass through the bore 49C of the piston. Itis to be noted that the slide 6 at the muzzle and the piston 44 in thebore of the tube 2 serve to accurately guide the spear. As it leaves themuzzle the spear tailpiece 46 engages the retrieving slide 6 and, asabove, pulls the slide, the cord 23 and the bridle cord 26 with it as itleaves the gun. The spear travels and is retrieved as in thehydro-pneumatic gun above. As in the hydro-pneumatic arrangement thereis no loss of air in the pneumatic arrangement and the spear may bereloaded and tired repeatedly without the necessity of recharging theair chamber.

In the use of pneumatic type spear guns it is to be noted that the spearpropelling member, or pistonv which is used to eject the spear from thebarrel, is subjected to very high impact and deceleration stresses whichare, in turn, transmitted to the muzzle, or stop means members of thegun. In the conventional pneumatic spear guns, various decelerationmeans such as a mechanical spring incorporated in the muzzle or mbberwashers attached to the piston have been utilized for shock absorption.Springs, however, are subject to deterioration and breakage due to thecorrosive action lof sea water. Rubber washers are subject todeterioration, splitting, permanent deformation and add unnecessaryweight to the piston creating a greater mass which must be decelerated.The improved, air operated piston shock absorbing muzzle described inconnection with FIG. 5 obviates the limitations of these prior devices.

An alternate dual piston assembly as illustrated in FIG. 10 providesanother form of air operated piston shock absorbing muzzle for use onpneumatic type spear guns. A piston assembly 53 includes a drivingpiston 54 and a deceleration piston 55 of tubular shape. The drivingpiston 54 has its rear portion shaped with an' annular flange 54a whichforms a latching shoulder for engagement with latch 30 described above.A diametral recess 54b which is provided to reduce weight and is formedin the rear of the piston 54 connects with a smaller air passage 56.Forward of and connecting with recess 56 is a concentric bore of alarger diameter which terminates in a still larger diameter providedwith internal threads. A transverse hole 57 formed in the wall of piston53 is disposed adjacent the forward end of recess 56 and acts as anorifice for the passage of air into and out of the enlarged innerrecess. An O-ring 58 is mounted in an annular groove in the externalsurface of an enlarged rear portion of piston 54. This O-ring acts as apiston ring to seal the piston 54 within the tube bore 2c. A conicalvalve seat 59 is provided at the junction of the larger bore and airpassage 6 and the orifice 57. Deceleration piston 55 is provided with anexternal groove within which is mounted an O-ring 61 which acts as apiston ring between the piston and tube bore 2c while in the same pistonan internal groove is also provided for the mounting therein of anO-ring 62 which acts as a piston ring seal between piston 55 and aforward reduced external diameter 54C of piston 54. Mounted in thelarger internal bore portion of piston 54 is a cylindrically shapedneedle Valve member having a conical inner end adapted to engage andprovide a sealing means with the valve seat 59. The left or enlarged endof the valve is formed with an external thread 63a to threadedly engageand be manipulatedly mounted to the threaded forward portion of theenlarged recess of piston 54. Inwardly of the threaded portion of theneedle valve 63 there is formed in the reduced shank portion an annulargroove adapted to receive an O-ring 64 which provides a seal for thebore portion of the piston 54 which carries the needle valve. Theexternal forward end of the piston portion 54C is formed with a taper54d which is preferably a locking taper adapted to engage a taperedrecess 66a of a spear 66. Adjacent taper 54d there is formed in reduceddiameter 54C a groove adapted to engage and hold a snap or retainingring 69 which forms a forward stop or shoulder for the retention of thepiston 55 on the diameter 54e. Muzzle stop member 65 of generallytubular shape is formed with an internally threaded portion adapted tobe threadedly mounted on the forward end of tube 2. A reduced concentricbore 65a is formed at the forward end of member 65, said bore slidablyreceiving the shaft portion of spear 66. A shoulder 65b extendingbetween the two different sizes of bores provides a stop means for theforward motion of the piston assembly 53. An external annular flange 65eis formed on stop 65, said flange having transversely drilled holes 65dthrough which is secured retrieving cable 23. Stop member 65 is formedat its forward end with an external taper upon which is mounted a spearretrieving slide 67 to be more fully described later. The cord 26 isfastened to slide 67 and the operation is similar to the operationdescribed above.

The operation Yof the dual pist-on assembly 53 olf FIGS. and l1 is asfollows: Prior to charging the gun with compressed air the needle valvemember 63 of driving piston 54 is screwed outwardly two or three turnsso as to permit the ilow of air through the air passage 56, thencethrough orifice 57 and into air chamber 70. Air chamber 70 consists ofthe volumetric area surrounding the reduced diameter 54C and is disposedbetween the rear face of deceleration piston 55 and the forward face ofdriving piston 54 and is enclosed by the wall of tube 2. The gun ischarged with compressed air. As the pressure is increased within the airchamber 7a and the barrel 2c, it is similarly increased within the airchamber 70 of the piston assembly. When the desired internal pressure isreached, the needle valve member 63 is screwed inwardly to close off theconical valve seat 59 thus forming the pressurized slidable pistonassembly 53. The tailpiece of the spear 66 is now inserted into the openend of muzzle member 65 'and is mounted on the tapered projection 54d ofthe driving piston 54. The gun is now ready to be cocked and iired inthe manner previously prescribed in connection with FIG. 5. In FIG. l1is shown the piston assembly just prior to reaching the stop shoulder6512 of the muzzle member 65 and it is to be noted that the spearshoulder 66d has not yet reached the retrieving slide 67. In FIG. 10 thepiston, spear, and slide are shown at the moment the deceleration piston55 contacts the stop shoulder 651; of the muzzle 65. It is to be notedthat the tapered portion 66p` of the spear 66 has reached the `slide 67.As the deceleration piston 55 is stopped by the muzzle member 65, thedriving piston 54 continues to move forward thereby further increasingt-he pressure in the air chamber 7 (l` until the internal pressuretherein decelerates and stops the forward movement of the drivingpiston. The forward moving spear 66 then pulls free yof the drivingpiston and the slide 67 with bridle 26 and cable 23 is carried by thespear as it emerges from the muzzle.

FIG. 12 also shows the hydro-pneumatic gun of FIGS. l and 2 but with themuzzle section altered to utilize the spear 66 and retrieving slide 67of the pneumatic embodiment shown in FIG. 10. In FIG. l2, the spearadapter 71 is slidably disposed to the rear of spear 66 and threadablysecured in the threaded recess 66h thereof. It will be noted that, withthe exception of the tapered threaded forward section 71a the adapter 71is identical to the spear adapter 28 of FIG. 2 and previously described.An O-ring seal 72 carried in a groove in adapter 71 acts as a pistonring `to seal the adapter 71 in the bore 2c of the firing tube 2. Exceptlfor the slightly enlarged bore 73a which is formed as a continuation ofthe outer end of the bore 2c, the muzzle nosepiece member 73 isidentical to the muzzle member 65 of the embodiment slrown in FIG. 10and previously described. The rear, reduced radius portions of theretrieving slide 67 are slidably disposed within bore 73a of the muzzlenosepiece 73 and serve to center the spear in the barrel. The gun iscocked and fired in the same manner as the gun previously described andillustrated in FIGS. l and 2.

FIG. 14 illustrates the embodiment of the muzzle and barrel piston ofthe `gun of FIG. 5, however a modified muzzle piston 74, spear 75 andtailpiece 76 are used to utilize the retrieving slide of 67. Except forthe reduced diameter 76a which is slightly smaller than the diameter ofthe spear, the spear tailpiece 76 is identical to the tailpiece 46 ofthe gun shown in FIG. 5. Muzzle piston 74 is `similar to muzzle piston49 (FIG. 5) but is provided With a reduced interna-l diameter 74a whichis slightly larger than the diameter of the spear 75 and provides asliding t between spear and diameter 74a. Spear 75 is similar to thespear 21 of FIG. 5 except that an external tapered portion 75a isprovided forward of tailpiece 76 to form a stop shoulder 75b for theengagement thereby of retrieving slide 67. The manner of operation ofthe gun is similar to the gun of FIG. 5.

The conventional spear retrieving slide is usually provided with a boredhole of substantially the same diameter as the spear shaft and isislidable thereon. The tailpiece, or rear of the spear, is usuallyprovided with a slightly larger diameter than the spear shank in orderthat the shoulder provided by this larger rear piece will engage yorcatch the retrieving slide upon leaving the barrel. Although this methodIas described is effective, difliculty is `often encountered in thepassing of the large diameter tailpiece through the rnuzzle of the gunwithou-t impinging some part of the muzzle. This impingement can causethe spear to be deflected from its line of flight and seriously affectits accuracy. The probability of irnpingement has been overcome in thepresent invention by the utilization of the tapered rear section 6a asdescribed in conjunction with and shown in FIGS. 2 and 5. This taperedrear section insures that the rear of the spear is centered in the boreand in the muzzle as it is ejected. In addition to the method as used inFIGS. 2 and 5 there is another approach to this problem and in thisconnec` 1 1 tion the tailpicce is made the same diameter or smaller thanthe shank of the spear. This reduced size provides for the eliminationlof any shoulders or protrusions which may impinge Von the muzzle.

The embodiment showing a reduced diameter tailpiece is shown in FIG. 10and includes a spear 66 which is similar in all respects to the spearillustrated in FIGS. 2 and 5. The tailpiece of this spear 66 ispreferably an integral part of the spear and is provided with aninternal tapered recess 66a which is adapted to accept the conical taper54d of the driving piston 54. The forward end of the tapered `recess 66ais provided with an internal thread 66b in which is threadedly mountedthe tailpiece adapter 71 of the hydro-pneumatic embodiment of FIG. l2described above. Just forward of the thread 66h the external diameter ofthe `spear is provided'with a conically tapered portion 66e terminatingat the smaller end in a shoulder portion 66d. Mating with taper 66C `andtetrminating iat shoulder 66d is retrieving slide 67. FIG. 9 shows afrontal view yof this slide 67 with a fragmentary portion in section toillustrate the method of assembly. This slide 67 is essentiallycomprised of two similar halves 67a preferably made 'of steel and which,when assembled, form the slide member 67, the assembly being pivotallyand slidably disposed about the .spear shaft 66. Each member 67a isformed with a tapered semi-tubular rearward portion and with a largerexternal radial portion forwardly thereof which radial portion isprovided with a radial groove or recess adapted to accept an elasticband 68. The forward end of the slide member 67a is provided with Iasmall diameter pin projection 67h and with a hole of slightly largerdiameter 67C diametrically opposite thereto and a transversely extendingear provided with a hole 67d to `accept one end of the bridle 26 whichis knotted and secured thereto. FIG. 13 illustrates the members 67a justprior to assembly in which it is noted that by engaging the pins 67bwith their respective matching holes 67C the completed assembly willprovide an internal diameter which is free to slide over spear shaft 66.It is to be further noted that when the [members 67a are assembled as inFIGS. 9 and 14 the slide assembly 67 will be a mating t with the shaftand the elastic band 68 when mounted in the groove adjacent the earportions will urge the members 67a about the spear shaft 66. When thespear has been fired, the shaft will move forwardly in the barrel andslide `assembly 67 and upon reaching the slide 67 the taper 66C of thespear will allow the rear portions of the two halves to move inwardlytoward each other and as urged by the elastic band 68 to close about thetaper 66C and engage the spear shoulder 66d. Thus engaged the slide 67will be carried by the spear 66 as it leaves the gun.

Convertible hydro-pneumatic, pneumatic spear gun An embodiment of aconvertible spear gun adapted to be changed from and to ahydro-pneumatic method and from and to a pneumatic method is shown inFIGS. 15 and 16. This gun uses nearly all the components seen in FIG. 5and those not identical are similar in shape and function and areadapted for the conversion to be described. This convertible gunincludes a handgrip 111 similar to handgrip 1 except that a recess 112is formed in the grip portion. Tube 2 is mounted on the handgrip 111 inthe manner of FIG. 5 and carries a `spear 21 having a point 22 mountedthereon. A threaded recess 2lb described in conjunction with FIG. 5carries a shouldered stud 80 having an engaging collar 81 `formedthereon. A shaped end 82 of reduced size may be in the form of a square,hex or screwdriver point and extends beyond collar 81. A screw plug 83having a recess in its outer or left end and adapted to receive and bedriven by the shaped end S2 is threadedly mounted in a piston 84. A reartube 7 forming the outer wall of 'a compression chamber has its rear endclosed by a valve retainer 12 and `O-ring 13. Sheck valve 14, O-ring 15,plug 16,

O-ring 17 and loop 18 are mounted in and function in retainer 12 thesame as previously described. A compression spring lies adjacent theinner wall of tube 7 and serves a dual purpose. When in the expandedposition of FIG. 16 the ends of the spring engage retainer 12 and piston84 and urge piston 84- forwardly against handgrip end 86. In the bore ofpiston S4 there is a counterbore portion 87 adapted to rotatably receiveand retain a larger outside diameter of the screw plug 83. An O-ring 88is mounted in an annular recess formed in the bore 87 of the piston 84.A cross-bore and bleeder passageway 90 is formed from the inner end andextends forwardly to terminate at the bore 87. A threaded portion 92 ofthe plug 83 has a radial external groove formed near its inner end, saidgroove having mounted therein a snap or retaining ring 94 which providesa stop for the outward screwing of the plug 83.

In form the gun of FIG. 15 is arranged to be used as a hydro-pneumaticgun, the nosepiece assembly 47 is removed from flanged adapter 4 and isstored in the recess 112. As shown, the tapered muzzle portion of thenosepiece is mounted on a rubber button or shoulder piece 96. Thethreaded end of the nosepiece is held in place by a rubber plug 98having a spherical end adapted to engage the inner edge of the threadedend. The resilience of the spherical end of the plug permits thenosepiece to be snapped into and out of the recess 112. Inhydro-pneumatic operation the screw plug is turned all the way inwardlyby manipulation of the spear 21 and by using barb 99 as a wrench handleto turn the shaped end 82 and engage screw plug 83.

A spear piston piece or plunger 160 as seen in FIG. 16 includes acentrally formed diametral lrecess adapted to receive the reducedportion of stud 80 including the collar portion 81 and shaped end 82.The outer portion of the piston 100 has a cylindrical portion slidablein the tube 2 and a reduced portion 101 and an annular ange 102. Thisshaped end of portion 101 and flange 102 is adapted to engage the latch30 described above and which is move-d in response to the trigger 35. Inthe larger diameter portion of piston 160 there is formed a groove inwhich O-ring 103 is seated and acts as a piston ring seal in tube 2. Alateral recess 104 is also formed in the side of the larger diameter andmounted therein is a `spring 105 retained there by the head of a screw106 mounted in a tapped hole in the piston body. Spring 105 has its freeend formed with a V-shaped engaging portion arranged to engage collar 81of stud 80 when the stud is inserted into the piston.

Operation as hydro-pneumatic ,gunV

To use the 'gun of FIG. 15 as a hydro-pneumatic gun the spear 21 haspiston 100 removed from the stud S0 and by means of shaped end 82 thescrew plug 83 is turned all the way in to form a compression chamberwithin tube '7. This chamber is charged with air in the manner describedin conjunction with FIG. 2 above. Nosepiece 47 is removed from theadapter 4 and stored in recess 112 in the handgrip 111. Piston 100 ismounted on stud 80 and with the gun barrel or tube 2 filled with waterthe gun is cocked or armed and then fired in the manner described abovein conjunction with FIG. 2.

OperalionA as pneumatic gun To use the gun of FIG. 15 as a pneumatic gunthe piston 100 is removed from spear 21 and by means of shaped end 82and barb 99 the spear is rotated so as to engage and turn screw plug 83outwardly until retaining ring 94 reaches or nearly reaches the innerend of piston 84. After being screwed out so that the larger diameter ofthe screw plug 83 is outside counter bore 87 the passageway 90 will beopen from the compression chamber inside tube 7 and to the taperedpassageway 9 within the handgrip 111. Piston 100 is inserted in bore 2cand nosepiece 47 is removed from recess 112 and then mounted on adapter4 as shown in FIG. 16. The chamber 7 and tube 2c is charged with airthrough check valve 14 in the manner described in conjunction with FIG.5. The gun is cocked or armed by inserting stud 80 in the recess inpiston 100 `and pushing piston 100 inwardly until reduced portion 101and ange 102 engage the latch 30 in the manner described for the guns ofFIGS. 2 and 5. When tired the piston 100 is rapidly moved to the muzzlewhereupon the forward shoulder of the piston 100 engages the piston 49of the nosepiece 47 the piston 49 decelerates and stops the piston 100whereupon the ycollar 81 acts as a cam to lift and disengage itself fromthe V-portion of spring S and spear 21 is free to move forwardly in themanner of FIG. 5.

In FIG. 17 is shown a simplified shock absorber muzzle for use in thegun when used in pneumatic form. In this embodi-ment an adapter 120 isformed with a threaded recess 121 with which to engage and be mounted onthe threaded portion 2b of tube 2. A reduced bore 122 extends fromabo-ut midpoint of adapter 120 t-o the forward end of the adapter. Thisbore 122 is` sized so as to slidably accept a shoulder portion 124 ofspear stud 125. A piston 126, slidable in tube 2, has a rear portionshaped with a reduced portion 127 and a flange 128 adapted to engage thelatch 30 described above. Within the main cylindrical portion 129 of thepiston 126 there is a lateral recess 130I similar to recess 104 and inthis recess 130 there is mounted the spring 105` and screw 106 mountedas in FIG. 16'. Also in cylindrical portion 129 there are formed twoIannular grooves within which are mounted O-rings 132 and 133 which actas piston rings when piston 125 is slid in tube 2. A forward portion 134of this piston has a passageway concentrically located therein andproviding 'a guide and sliding tit for stud 125. The outer diameter ofportion 134 is made a few thousandths of an inchsrnaller than bore 122.In use as a pneumatic gun, the gun arranged as in FIG. 17 will have thestud 125 pushed into piston 126 until the reduced end of the stud isengaged by spring 105 which prevents accidental dislodgement. Shoulder124 engages the forward end of portion 134 and as the spear is pushedinto the tube 2, piston 126 will be pushed inwardly to compress furtherthe air in the compression chamber and tlange 128 will be engaged bylatch 30. When the gun is tired, the piston 126 will move rapidlyforward in tube 2 and the water around the shaft of the spear will beexpelled with the spear. When portion 134 enters bore 122 the watertrapped by the `advancing piston 126 in `larger bore 2c must be expelledthrough this small circular orifice formed by the predeterminedclearance fbetween portion 134 and bore 122. Selective clearance betweenthese pieces will provide the desired checking action. As piston 126` isdecelerated and stopped the spear travels forwardly with the collarportion on the stud 125 camming the spring 105 out of the way and thestud 125 sliding out of the passageway.

It is to be noted that spring 85 in the compression chamber in additionto acting as a brake on the rotation of piston 84 also acts to provide apropulsive force on the piston 84. When the gun is cocked, piston 84 ismoved rearwardly causing spring 85 to be compressed to nearly its shutheight and when tired spring 85 will act with the compressed air to urgethe piston 84 forward.

I wish it to be understood that the forms of the invention shown anddescribed herewith, are presented as preferred embodiments of the same,and that other forms and constructions within the scope of the claimsmay be resorted to without departing from the spirit of the in- Vention.

I claim:

1. A hydro-pneumatic spear gun adapted for use in underwater sports andthe like, said gun comprising (l) a handgrip having a communicatingthrough passageway and a latchbore transversely disposed to thecommunicating passageway, (2) a tiring tube mounted on said handgrip andconnecting with the communicating passageway, the tube adapted to befilled with liquid, (3) a spear of conventional shape and having apiston means at its rear end adapted to slide in and seal the bore ofthe ring tube as the spear is inserted in the tube, the spear alsohaving a latch engaging means provided in its rear portion, (4) achamber means for compress-ed air and the like and connected to thecommunicating passageway and a piston movable in the chamber andresponsive to the insertion of the spear in the firing tube to move thepiston and to compress further the air in the chamber, (5) a latch meanscarried in a latch bore and having piston portions of differingdiameters and movable by one of the diameter portions of said piston inresponse to the fluid pressure thereon developed in the barrel by theinsertion of the spear in the barrel to move the latch means into spearengaging position, and (i6) a trigger means carried by the handgrip andadapted to move the latch member to a disengaging position, whereby whenthe piston end of the spear is mounted in the firing tube submerged influid and is pushed into the tube the fluid in the tube furthercompresses the air in the compression chamber and urges the latch intothe engaging position and when the spear is fully inserted thepressure-actuated latch will engage the latch engaging means on thespear to retain the gun in armed position until the trigger means isactivated to move the latch member to release the spear.

2. A spear gun as in claim 1 in which the dual diameter piston portionsof the latch member have a uid sealing means on each diameter and afluid conducting means from the communicating passageway to a positionintermediate the diameter seals.

3. A spear gun as in claim 2 in which the trigger means includes asafety mechanism for limiting the tiring actuation movement of thetrigger means, said safety mechanism including a movable safety memberhaving a piston receiving bore therein, a lug on the movable safetymember adapted to slide in a guideway formed in the handle, the lugmovable from the end of the guideway and to a position against ashoulder stop formed in the handle, the stop adapted to hold the lug ina locked position, a piston carried in the piston receiving bore andhaving one end arranged to engage the trigger means and the other endcarried in the bore, a sealing means on the piston adapted to provide apressure seal as the piston is moved in the bore and means to coniineone end of the bore to provide a compression chamber by which thecompressed air therein provides a resilient bias which tends to urge thepiston out of the bore whereby when the movable safety member is movedforwardly the lug is moved to the end of the guideway whereupon theouter end of the piston will engage the trigger to resiliently urge thetrigger into the cocked position and when the lug is moved from theguideway to the stop the compression chamber will provide frictionalengagement of the lug to-the stop while the forward face of the safetymember will provide a secondary positive stop to prevent the triggerfrom being moved an amount sufficient to move the latch to the firingposition.

4. A spear gun as in claim 3 in which the chamber means for compressedair includes a tube having a piston slidably retained therein and thechamber further having air inlet means for charging the chamber and aweight disposed in the chamber to provide a counterbalancing weight tothe ring tube and the provide an inertia dampening effect to thereaction of the tiring Iof the gun.

5. A pneumatic spear gun adapted for use in underwater sports and thelike, said gun comprising (l) a handgrip having a communicating throughpassageway and a latch bore transversely disposed to the communicatingpassageway, (2) a ring tube mounted on the handgrip and connecting withthe communicating passageway, (3) a piston slidable in the bore of thetiring tube and having a sealing means mounted on the piston to seal the.outerward travel of the firing tube piston as it moves toward themuzzle, a spear of conventional shape and having a piston engaging meansat its rear end ,by which means the spear is releasably retained andaligned in the firing tube, (6) a chamber means for compressed air andthe like and connected to the communieating passageway to provide withthe piston in the firing tube a chamber whose size varies as the firingtube piston is moved in the tube to vary the air pressure in thechamber, (7) a latch means carried in a latch bore and having pistonportions of differing diameters and movable by one of the diameterportions of said piston in response to the fluid pressure thereondeveloped in the barrel by the insertion of the spear in the barrel tomove the latch means into engaging position, (8) a latch engaging meansformed on the firing tube piston and adapted to be releasably engaged bythe latch member to retain the piston in an armed condition, (9) atrigger means carried by the handgrip and adapted to move the latchmember to a disengaging position, whereby when the firing tube piston isengaged by the spear and is pushed down the barrel to latching positionthe compressed air in the tube and chamber is further compressed andlatch member is urged into engaging position to hold the spear andpiston in the armed position until the trigger means is activated tomove the latch member to release the spear.

6. A spear gun as in claim 5 in which the latch member is a pistonhaving at least two different diameters and an air pressure sealingmeans on each diameter and an air pressure conducting means from thecommunicating passageway to a position intermediate the diameter seals.7. A spear gun as in claim 6 in which the trigger means includes asafety mechanism for limiting the tiring actuation movement of thetrigger means, said safety mechanism including a movable safety memberhaving a piston receiving bore therein, a camming means on the movablesafety member adapted to slide in a guideway formed in the handle, thecamming means movable from the end of the guideway and to a positionagainst a shoulder stop formed in the handle, the stop adapted to holdthe camming means in a locked position, a piston carried in the pistonreceiving bore and having one end arranged to engage the trigger meansand the other end carried in the bore, ya sealing means on the pistonadapted to provide a pressure seal as the piston is moved in the boreand means to confine one end of the bore to provide a compressionchamber by which the compressed air therein provides 'a resilient biaswhich tends to urge the piston out of the bore whereby when the movablesafety member is moved forwardly the camming means is moved to the endof the guideway whereupon the outer end of the piston will engage thetrigger to resiliently urge the trigger into the cocked position andwhen the camming means is moved from the guideway to the stop thecompression chamber will provide frictional engagement of the cam to theStop while the forward face of the safety member will provide asecondary positive `stop to prevent the 4trigger from being moved anamount sufficient to move the latch to the ring position.

8. -A spear gun as in claim 6 in which the nosepiece means for checkingthe forward motion of the tiring tube piston has a shock absorbingmechanism using a pneumatic chamber and includes (l) an outer nosepiecehaving means for mounting the sleeve on the muzzle end of the barrel andhaving an inner surface with at least two concentric diameters ofdifferent extent, (2) an inner piston member having an outer surfacewith at least two lconcentri-c diameters of diiTerent extent, thediameters adapted -to mate to slide in the like-sized inner diameters ofthe outer nosepiece, (3) means for sealing each of the mating diametersas the inner piston member is moved in the bore of the outer nosepiece,(4) a compression chamber formed of the inner surface of the larger boreof the outer nosepiece,- the outer surface of the smaller diameter ofthe inner piston member and the shoulders extending from the larger tothe smaller diameters of the respective outer nosepiece and inner pistonmember, the compression chamber being reduced in volume as the innerpiston member is moved to bring the shoulders toward each other, and (5)means to limit the movement of the inner piston member to keep the innersleeve mounted in and slidable in the bore of the outer nosepiece.

9. A spear gun as in claim 8 in which the outer nosepiece is providedwith an air inlet means to the compression chamber.

10'. A spear gun as in claim 6 in which the nosepiece means includes apositive stop for the piston assembly slid-able in the firing tube borethe piston assembly including an outer member slidable in the tiringtube bore the member having an inner concentric bore, a sealing meansbetween 'the member and tiring tube, a piston having a piston portionslidable in the tiring tube bore and having a sealing means to seal thepiston portion in the bore, the piston having a latch engaging portionformed on the piston portion, a reduced forward shank portion on thepiston the reduced shank slidable in the inner bore of the ring tubemember, a sealing means in the inner bore of the member to seal thepiston and member, a stop means adapted -to limit the maximum travel ofthe piston shank in the firing tube and to retain the plunger in thetiring tube, the minimum travel limit provided by the end of the firingtube member and the inner shoulder of the piston portion of thepistonand closable air inlet means from the ring tube bore through thepiston and to the outside of the reduced shank portion at a pointnormally intermediate the tiring tube member and the piston portion ofthe piston whereby the air inlet means is opened the air under pressurein the firing tube is permitted to enter the circumferential chamberformed by the space between the reduced shank portion of the piston andthe firing tube and the air inlet is closed to leave thiscircumferential chamber to act as a pneumatic cushion as the spear istired and the piston assembly -is moved to the nosepiece means.

11. A spear gun for use in underwater Sports and the like, the gunadapted for use as both a hydro-pneumatic and a pneumatic method ofoperation and having certain members movable and removable for mountingand storage in and on the gun so as to convert the gun from one methodto another method of operation, said gun ineluding (l) a handgrip havinga communicating through passageway, (2) a firing tube mounted on saidhandgrip and connecting with the communicating passageway, (.3) achamber means for compressed air and the like and connected to thecommunicating passageway and provided with an air inlet means forcharging the chamber, (4) a piston movable in said chamber, (5) a valvein the chamber piston and adapted to be closed and Opened to render thepiston responsive and non-responsive to an external pressure applied tothe piston, (6) means to remotely manipulate the valve in the chamberpiston, (7) a piston movable in the tiring tube, (8) a spe-ar having ashank end adapted to engage and be removably retained Iby the tiringtube piston, (9) a trigger means carried by the handgrip andmanipulatedly adapted to engage, retain and release the tiring tubepiston, (10) a nosepiece adapted to be removably mounted on the muzzleof the firing tube and when mounted to provide a stop for the piston,and (1-1) storage means for retaining the nosepiece in the gun While thenosepiece is removed from Athe muzzle, whereby when the gun is arrangedfor pneumatic operation the valve in the chamber piston is opened Itopermit the compression cham-ber to freely communicate with the tiringtube, the tube piston is placed in the ring tube and the nosepiece ismounted on the tube to provide a muzzle stop for the tube piston as itis red, and whereby the gun is arranged for hydro-pneumatic Operationthe nosepiece is removed from the firing tube and sto-red in the storagemeans, the tube piston is removed from the tube and is mounted on theshank end of the spear and the valve in the chamber piston is closed sothat the firing tube may be iilled with water before inserting the tubepiston and spear shank.

12. A spear :gun as in claim 11 in which the trigger means includes (1)a latch bore transversely disposed to the communicating passageway inthe hand grip, (2) a latch piston having at least two differentdiameters and a pressure sealing means on each diameter and apressure-conducting means on each diameter and a pressureconductingmeans from the communicating passageway to a position intermediate thediameter-sealing means, and (3) a safety mechanism for limiting thetiring actuation movement of the trigger means.

i13. A spear gun as in claim 12 in which the safety mechanism includes amovable safety member having a piston receiving bore therein, a lug onthe movable safety member adapted to slide in a guideway formed in thehandle, the lug movable from the end of the guideway and to a positionagainst a shoulder stop formed in the handle, said shoulder stop adaptedto hold the lug in a locked position, a piston carried in the pistonreceiving bore, biasing means for urging the piston forwardly in thebore, whereby when the movable safety member is 'moved forwardly the lugis moved to the end of the guideway whereupon the outer end of the.piston will engage the trigger to resiliently urge the trigger into thecocked posi tion and when the lug is moved from the guideway to the stopthe biasing means will provide frictional engagement of the cam to thestop while the forward face of the safety member will provide asecondary positive stop to prevent the trigger from being moved anamount suflicient to move the latch to the firing position.

14. A spear gun as in claim 13 in which the biasing means urging thesafety piston forwardly includes the piston with one end carried in thepiston receiving bore of the safety member and with the other endarranged to engage the trigger means, the piston having a sealing meanson that portion movable in the bore and adapted to provide a pressureseal as the piston is moved in the bore, and means to confine one end ofthe bore to provide a compression chamber by which the compressed airtherein provides a resilient bias which tends to urge the piston out ofthe bore.

15. A spear gun las in claim 14 in which the chamber means includes aspring mounted in the chamber and arranged to engage the piston movablein the chamber and to urge the piston toward one end of the chamber andin which the storage means for the nosepiece cornprises a recess in thehandgrip with a nosepiece engaging means disposed in the recess in thehandgrip.

16. A spear gun as in claim 11 in which the spear has its shank endprovided with a portion diminishing in diameter as it approaches the endof the spear, a shoulder portion formed at the end of the diminishedportion, a retrieving slide assembly adapted to be mounted on the spearand to be simultaneously seated in the nosepiece, the slide assemblyadapted to engage said shoulder por tion at the end of the spear as itis tired from the gun, the slide assembly including cable attachingmeans, a pair of like members pivotally surrounding the spear and heldin slidable engagement with the shank of the spear, a biasing means forurging the movement of two shank engaging portions tow-ard each other toprovide a shoulder engaging means when the shank portions are moved ontothe diminished portion of the shank and in the way of the shoulder onthe end of the shank of the spear.

17. A spear gun as in claim 12 in which the nosepiece has a rear portionadapted to be removably mounted on the muzzle of the firing tube and inwhich a front portion of determinate length has a -bore whose diameteris slightly less than the bore of the tiring tube, and in which thepiston movable in the -ring tube has a forward diameter portion ofdeterminate length and whose outer diameter is a few thousandths of aninch less than the front bore portion of the nosepiece so that when thepiston is pushed into the nose piece the rear portion 'of the piston isable to engage and be stopped by the internal shoulder in the nosepieceand the forward bore of the nosepiece and inserted forward pistonportion will have a circular clearance each with the other to therebyprovide a circular orifice for controlling the rate and duration of theflow of liquid from the barrel as the gun is fired.

References Cited by the Examiner UNITED STATES PATENTS 2,900,972 8/ 1959Marsh et al. 2,923,285 2/1960 Salles 124-13 2,923,286 2/ 1960 Draganti124-13 RICHARD C. PINKHAM, Primary Examiner. W. R. BROWNE, AssistantExaminer.

1. A HYDRO-PNEUMATIC SPEAR GUN ADAPTED FOR USE IN UNDERWATER SPORTS ANDTHE LIKE, SAID GUN COMPRISING (1) A HANDGRIP HAVING A COMMUNICATINGTHROUGH PASSAGEWAY AND A LATCHBORE TRANSVERSELY DISPOSED TO THECOMMUNICATING PASSAGEWAY, (2) A FIRING TUBE MOUNTED ON SAID HANDGRIP ANDCONNECTING WITH THE COMMUNICATING PASSAGEWAY, THE TUBE ADAPTED TO BEFILLED WITH LIQUID, (3) A SPEAR OF CONVENTIONAL SHAPE AND HAVING APISTON MEANS AT ITS REAR END ADAPTED TO SLIDE IN AND SEAL THE BORE OFTHE FIRING TUBE AS THE SPEAR IS INSERTED IN THE TUBE, THE SPEAR ALSOHAVING A LATCH ENGING MEANS PROVIDED IN ITS REAR PORTION, (4) A CHAMBERMEANS FOR COMPRESSED AIR AND THE LIKE AND CONNECTED TO THE COMMUNICATINGPASSAGEWAY AND A PISTON MOVABLE IN THE CHAMBER AND RESPONSIVE TO THEINSERTION OF THE SPEAR IN THE FIRING TUBE TO MOVE THE PISTON AND TOCOMPRESS FURTHER THE AIR IN THE CHAMBER, (5) A LATCH MEANS CARRIED IN ALATCH BORE AND HAVING PISTON PORTIONS OF DIFFERING DIAMETERS AND MOVABLEBY ONE OF THE DIAMETER PORTIONS OF SAID PISTON IN RESPONSE TO THE FLUIDPRESSURE THEREON DEVELOPED IN THE BARREL BY THE INSERTION OF THE SPEARIN THE BARREL TO MOVE THE LATCH MEANS INTO SPEAR ENGAGING POSITION, AND(6) A TRIGGER MEANS CARRIED BY A HANDGRIP AND ADAPTED TO MOVE THE LATCHMEMBER TO A DISENGAGING POSITION, WHEREBY WHEN THE PISTON END OF THESPEAR IS MOUNTED IN THE FIRING TUBE SUBMERGED IN FLUID AND IS PUSHEDINTO THE TUBE THE FLUID IN THE TUBE FURTHER COMPRESSES THE AIR IN THECOMPRESSION CHAMBER AND URGES THE LATCH INTO THE ENGAGING POSITION ANDWHEN THE SPEAR IS FULLY INSERTED THE PRESSURE-ACTUATED LATCH WILL ENGAGETHE LATCH ENGAGING MEANS ON THE SPEAR TO RETAIN THE GUN IN ARMEDPOSITION UNTIL TH TRIGGER MEANS IS ACTIVATED TO MOVE THE LATCH MEMBER TORELEASE THE SPEAR.